Patent Number: 6,253,260

Title: Input/output data access request with assigned priority handling

Abstract: Disclosed is a system and method for processing a data access request (DAR). A processing unit, such as a storage controller, receives a DAR, indicating data to return on a channel, such as a channel connecting to a host system, and priority information for the received DAR. The processing unit retrieves the requested data for the received DAR from a memory area, such as a cache or direct access storage device (DASD), and determines whether there is a queue of data entries indicating retrieved data for DARs to transfer on the channel. The queued DARs include priority information. The processing unit processes at least one data entry in the queue, the priority information for the data entry, and the priority information for the received DAR to determine a position in the queue for the received DAR. The processing unit then indicates that the received DAR is at the determined position in the queue and processes the queue to select retrieved data to transfer on the channel to the host system.

Inventors: Beardsley; Brent Cameron (Tucson, AZ), Iskiyan; James Lincoln (Tucson, AZ), Yudenfriend; Harry Morris (Poughkeepsie, NY)

Assignee: International Business Machines Corporation

International Classification: G06F 3/06 (20060101); G06F 003/00 (); G06F 013/28 (); G06F 013/00 (); G06F 013/14 ()

Expiration Date: 06/26/2018